On 04/26/2013 11:03 AM, Nathan Moore wrote:
> Context: small academic cluster of SL5.8 machines, x86_64.
>
> Recently, some of the machines on the cluster stopped being able to
> access the outside internet.  Machines can still update via ftp, yum,
> nslookup, and ping, but http requests beyond the local cluster seem to
> be universally denied.  I've never encountered a problem like this
> before (and it is probably my own fault, as I am a self-taught
> sys-admin), but I'm wondering if anyone else has seen a similar problem.
>
> Bonus points if you can tell me where in /etc  or /var I should look to
> find the offending config file.

Sounds more like a firewalling, port-specific routing or corporate 
netnanny problem if they can send/receive other forms of traffic.